Navigating Our World Like Birds and Bees

African tribesmen walk through their landscape in a pattern that eerily echoes the movements of scavenging birds, flocking insects, gliding sharks and visitors to Disneyland, a new study finds, suggesting that aspects of how we choose to move around in our world are deeply hard-wired.

For the new study, which appeared online recently in Proceedings of the National Academy of Sciences, researchers at the University of Arizona at Tucson, Yale University, the New York Consortium in Evolutionary Primatology and other institutions traveled to northern Tanzania to study the Hadza, who are among the last human hunter-gatherers on earth. The Hadza generally spend their days following game and foraging for side dishes and condiments such as desert tubers and honey, frequently walking and jogging for miles in the process.

The ways in which creatures, including people, navigate their world is a topic of considerable scientific interest, but one that, until the advent of global positioning systems and similar tracking technology, was difficult to quantify. In the past decade, however, scientists have begun strapping GPS units to many varieties of animals and insects, from bumblebees to birds, and measuring how they move.

What they have found is that when moving with a purpose such as foraging for food, many creatures follow a particular and shared pattern. They walk (or wing or lope) for a short time in one direction, scouring the ground for edibles, then turn and start moving in another direction for a short while, before turning and strolling or flying in another direction yet again. This is a useful strategy for finding tubers and such, but if maintained indefinitely brings creatures back to the same starting point over and over; they essentially move in circles.

So most foragers and predators occasionally throw in a longer-distance walk (or flight), which researchers refer to as a “long step,” bringing them into new territory, where they then return to short walks and frequent turns as they explore the new place.

This particular motion pattern was first scientifically identified in 1999 among scavenging albatrosses and termed a Levy flight or walk (named, for obscure reasons, after Paul Levy, a French mathematician). Since then, researchers have discerned the same pattern in bumblebees, sharks, fly fishermen trawling a river and people at amusement parks, who sample one portion of the facility in depth before ambling off to remoter rides.

But while the pattern was instinctual in animals and insects, it was not clear whether Levy-style movement was natural to humans or occurred in modern times almost by happenstance, because of how we built our cities and amusement parks.

So the scientists turned to the Hadza, who still live much as humans did millennia ago. They outfitted 44 of the tribespeople with GPS watches and asked them to hunt and gather for several days while wearing the units.

The resulting data showed that the tribespeople frequently employed the Levy walk, moving briefly in one direction, then shifting and covering nearby ground, until that area was exhausted of potential food, at which point they’d set off on a longer-distance hike to new ground and there begin the short explorations again.

This finding has surprising relevance, even for those of us whose food is arrayed in grocery aisles, said David Raichlen, an associate professor of anthropology at the University of Arizona who led the study. The GPS readings reinforce the likelihood that Levy-style walking patterns are hard-wired into the human brain and predict how we behave. Even before this study was published, he said, planners in some cities had used the theory that people Levy-walk — spending much of their time exploring one area, with occasional “long steps” or forays into another part of a city — to determine where to place cellphone towers. At a more individual level, he said, the discovery may help to explain why, after spending hours in a small, familiar office, many of us feel an itch to wander the halls in search of new geography.

But the most resonant implication of the study, Dr. Raichlen said, is that Levy walking patterns bind modern, urban humans to the natural world. “This pattern” of movement “emerges so often in so many different species and human societies,” he said. “It links us” to the flight of the albatross and to an ancient part of ourselves, even when we’re strolling toward Disney’s Tomorrowland.